有关dwr推送的笔记

时间：2023-01-20 05:35:06

想做一个web推送相关的东东，昨天搞了一天，终于把这些杂乱的配制弄清了，今天写出来方便以后记住，也方便大家看一下吧

1：引入dwr包，我用的是maven

<dependency>

    <groupId>org.directwebremoting</groupId>

    <artifactId>dwr</artifactId>

    <version>3.0.M1</version>

</dependency>

2：配制web.xml

我是在springMVC下进行的

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xmlns="http://java.sun.com/xml/ns/javaee"

    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

    version="2.5">

    <display-name>SmallSP Web Application</display-name>

    <listener>

        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

    </listener>

    <listener>

        <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>

    </listener>

    <context-param>

        <param-name>contextConfigLocation</param-name>

        <param-value>classpath:applicationContext.xml</param-value>

    </context-param>

    <servlet>

        <servlet-name>springMVC</servlet-name>

        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <init-param>

            <param-name>contextConfigLocation</param-name>

            <param-value>classpath*:mvc/springMVC.xml</param-value>

        </init-param>

        <load-on-startup>1</load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>springMVC</servlet-name>

       <url-pattern>/dwr/*</url-pattern>

    </servlet-mapping>

    <servlet-mapping>

        <servlet-name>springMVC</servlet-name>

        <url-pattern>/</url-pattern>

    </servlet-mapping>

    <servlet-mapping>

       <servlet-name>default</servlet-name>

       <url-pattern>*.js</url-pattern>

    </servlet-mapping>

    <filter>

        <filter-name>Set Encoding</filter-name>

        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

        <init-param>

            <param-name>encoding</param-name>

            <param-value>utf8</param-value>

        </init-param>

    </filter>

    <filter-mapping>

        <filter-name>Set Encoding</filter-name>

        <url-pattern>/*</url-pattern>

    </filter-mapping>

</web-app>

以上代码中添加的是以下这一段

<servlet-mapping>

        <servlet-name>springMVC</servlet-name>

       <url-pattern>/dwr/*</url-pattern>

    </servlet-mapping>

<servlet-mapping>

3：配制springMVC.xml

在原有springMVC配制中添加以下

    <dwr:configuration />

    <dwr:annotation-config id="dwr" />

    <!-- 要求DWR将util.js和engine.js映射到dwrController -->

    <dwr:url-mapping />

    <!-- 定义dwr -->

    <dwr:controller id="dwrController" debug="true">

        <dwr:config-param name="allowScriptTagRemoting" value="true" />

        <dwr:config-param name="crossDomainSessionSecurity" value="false" />

        <dwr:config-param name="pollAndCometEnabled " value="true"/>

        <dwr:config-param name="activeReverseAjaxEnabled" value="true"/>

        <dwr:config-param name="debug " value="true"/>

    </dwr:controller>

4：配制 RemoteProxy

@Controller

@RemoteProxy(name = "directController")

public class MyDwrController {

  @RemoteMethod

  public String ShowHello(){

      return "hello";

  }

  @RemoteMethod

  public void send(HttpServletRequest request,String msg){   

        ServletContext sc = request.getSession().getServletContext();

        ServerContext sctx = ServerContextFactory.get(sc);   

        //获得当前浏览 index.jsp 页面的所有脚本session

        Collection<ScriptSession> sessions = sctx.getScriptSessionsByPage("/show");

        Util util = new Util(sessions);

        ScriptBuffer sb = new ScriptBuffer();

        sb.appendScript("show(");

        sb.appendData(msg);

        sb.appendScript(")");  

        //推送

        util.addScript(sb);  

        //util.addFunctionCall("show", ": " + msg);

        //dwrtest为javascript函数

        }

}

5：发送页面

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>123</title>

<script type='text/javascript' src='/static/jquery-min.js'></script>

<script type='text/javascript' src='<c:url value="/dwr/engine.js"/>'></script>

<script type='text/javascript' src='<c:url value="/dwr/util.js" />'></script>

<script type='text/javascript'

    src='<c:url value="/dwr/interface/directController.js" />'></script>

<script type="text/javascript">

    function view() {

        directController.ShowHello(function(data) {

            alert(data);

        });

    } 

    function send(){

        dwr.engine.setActiveReverseAjax(true);

        directController.send($("#msg").val());

    }

</script>

</head>

<body>

      <input type="text" id="msg"  />

     <input type="button" value="发送" id="but" onclick="send();" />  

</body>

</html>

6：接收页面

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>Insert title here</title>

<script type='text/javascript' src='/static/jquery-min.js'></script>

<script type='text/javascript' src='<c:url value="/dwr/engine.js"/>'></script>

<script type='text/javascript' src='<c:url value="/dwr/util.js" />'></script>

<%-- <script type='text/javascript'

    src='<c:url value="/dwr/interface/directController.js" />'></script>  --%>

<script type="text/javascript">

    $(function(){

        //这句话千万不能少 ，表示允许使用推送技术

        dwr.engine.setActiveReverseAjax(true);

    });

    //这个函数是提供给后台推送的时候  调用的

    function show(msg){

        $("#message").text(msg);

    }

</script>

</head>

<body>

<div id="message" style="width: 200px;height: 200px;border: 1px solid red ; text-align: center; padding: 5px;"></div>

</body>

</html>

总结：就是以上步骤了。

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